Gate valve pressure lock



April 21,l 1953 A. G. sHEPPARD 2,635,633

Patented Apr. 21, V1953 i GATE VALVE PEES'S'URE LOOK Allan G. Sheppard, Elmira, ZN. I, assignor .to American-La France-Foamite Corporation, Elmira, N. Y., a corporation of New York Application November 15, 1946, serier No. 710,048

1 Claim.

This invention relates to gate valves of the kind used, for example, to control water flow to fire hose lines supplied by a pump; and it has for its object a valve of this general -character having effective provision for looking lthe flow control member of the valve at any desired degree of opening.

In valves of this type, utilizing a rotatable gate or flow control member located in the flow stream, the gate may readily hold its full open or full closed positions; but at intermediate settings, the pressure of -the stream is sulcient to move the gate unless some form of lock is provided. According to the present invention, as described at length below with reference to a preferred embodiment, provision is made for utilizing the pressure of the water s-tream to lock the gate at any desired position and without interfering with the free action of the gate as it is adjusted from one position to another.

In the accompanying drawings, Fig. 1 is a top plan view of a valve of the kind referred to above and Fig. 2 is a section on the line II-II of Fig. 1, the valve incorpo-rating an illustrative form of the invention.

The particular valve shown in the drawings is of a known type and need not be described in detail. As is well known and will be recognized, it includes a valve housing, generally designated I, having .a transverse flow passage controlled yby a gate or flow control member 2. The latter is rotatable to open and close the flow passage, having upper and lower stub shafts 3 and 4 journaled in the housing walls, the shaft 3 carrying the valve control handle 5 at its upper en-d. The foregoing elements and the indicated springsustained shoes 6 and l form no part of the invention and may be of standard or any preferred construction.

According to the invention, a part of the flow control member, or of an element associated with it, is arranged to loosely abut a portion of the housing, the said part normally being subjected, on both sides, to the pressure of the water stream when the'valve is open. In other words, the said part is normally balanced so far as the water pressure is concerned. And means is provided for relieving the pressure, at will, on the side of the said part abutting the housing, so that the full pressure of the Water is thereupon applied again free to move relatively to the said housing portion.

In the preferred form illustrated, a disc 8 is utilized, the disc being arranged coaxially with the flow control member and adapted for rotation with it. As Will be understood, the vdisc may vbe an integral part of the gate or may be Secured to it or simply keyed to the stub shaft 4. The disc overlies the wall 9 of housing l and, of course, its upper surface is subject to the pressure of the rwater in the flow passage. Provision is made -whereby the lower surface of the disc has restricted communication with the water flow passage, Which may result from the normal free fit of the parts or may be assured, as by a small bleed opening iii. Preferably, too, that portion of the housing wall 9 which the disc overlies is recessed, as at I I, in which event the bleed opening I may lead directly to the recess. It will be recognized that by the foregoing means the disc is normally balanced against any tendency of the water pressure to effect limited axial movement of the disc as would bind it against the wall 9, so that the gate is freely rotatable by handle 5.

Means is provided for venting the water pressure applied to the lower face of the disc to cause the disc, under the continuing lpressure applied to its upper face, to bind against the adjacent surface' of wall 9 and thereby lock the gate against rotation. Such means is shown as consisting of a valve l2 controlling an outlet |3 from the recess Il. The outlet l3 is of large capacity compared to the bleed opening lll and may discharge,

' through passage H4, to any point of substantially lower pressure than that within the valve housing, as to atmosphere or to the Suction side of the supply pump if such is used.

From the foregoing it will be understood that the vent or relief valve |2 is normally closed, the gate being adjusted to its required setting, as usual, without any interference from the disc. When the gate-is in the desired position, the vent valve is opened and the full water pressure thereupon applied to cause the disc to -bind against the adjacent surface of the housing and lock the gate against rotation. This condition continues just so long as the ven-t valve remains open, but the gate is readily unlocked for readjustment simply by closing the vent valve and i ithereby restoring the pressure balance to the disc.

In the light -of the foregong description the following is claimed:

A valve comprising in combination With a water flow passage incorporating a valve hous- References Cited in the flle of this patent UNITED STATES PATENTS Number :interior surface portion; said end Wall having a 10 Number :recess underlying a limited por-tion of said disc element and the latter having a bleed opening -therethrough providing restricted communication Vbetween the interior of the housing and said recess; and a valve for venting said recess.

ALLAN G. SI-IEPPARD.

Name Date Ord Apr. 27, 1909 Reynolds Feb. 3, 1914 Walker June 23, 1942 Volpin Oct. 20, 1942 FOREIGN PATENTS Country Date Great Britain Oct. 3, 1941 

